package com.study.homework.concurrent;

import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

public class CallableAndFuture {

	public static void main(String[] args) {
		ExecutorService threadPool = Executors.newSingleThreadExecutor();
		Future<String> future = threadPool.submit(new Callable<String>() {

			@Override
			public String call() throws Exception {
				Thread.sleep(2000);
				return "hello";
			}
		});
		System.out.println("等待结果");
		try {
//			System.out.println("拿到结果:"+future.get());
			System.out.println("拿到结果:"+future.get(1,TimeUnit.SECONDS));//超过时间没有拿到结果,报异常java.util.concurrent.TimeoutException
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		ExecutorService threadPool2 = Executors.newFixedThreadPool(10);
		CompletionService<Integer> completionService = new ExecutorCompletionService<>(threadPool2);
		for (int i = 1; i <=10; i++) {
			final int seq = i;
			completionService.submit(new Callable<Integer>() {

				@Override
				public Integer call() throws Exception {
					Thread.sleep(new Random().nextInt(5000));
					
					return seq;
				}});
		}	
		for (int j = 0; j < 10; j++) {
			try {
				System.out.println("qiguai"+j);
				System.out.println(completionService.take().get());
			} catch (InterruptedException | ExecutionException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		}
	}

}
